Is ${503300}$ divisible by $4$ ?
Solution: A number is divisible by $4$ if the last two digits are divisible by $4$ . [ Why? We can rewrite the number as a multiple of $100$ plus the last two digits: $ \gray{5033} {00} = \gray{5033} \gray{00} + {00} $ Because $503300$ is a multiple of $100$ , it is also a multiple of $4$ So as long as the value of the last two digits, ${0}$ , is divisible by $4$ , the original number must also be divisible by $4$ Is the value of the last two digits, $0$ , divisible by $4$ Yes, ${0 \div 4 = 0}$, so $503300$ must also be divisible by $4$.